Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 251703
AFDFSD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
1203 PM CDT Tue Jun 25 2019

.SHORT TERM...(Today through Wednesday Afternoon)
Issued at 352 AM CDT Tue Jun 25 2019

Band of warm air advection near 850 hpa leading to showers and
thunderstorms south of I-90 this morning.  This is expected to shift
east fairly quickly this morning leading to a dry day across the
region.  Still could see some mid level clouds around 10K feet or so
stream into western and southern portions of the forecast area. High
temperatures today will be fairly seasonal in the low to mid 80s.

As the flow becomes more southerly tonight, moisture increases and
with the gulf open could see some elevated storms develop. HRRR and
WRF_ARW are fairly quick to develop storms this evening, but
instability is fairly limited with initial moisture return.  Have
opted for slower timing than the hi res solutions.  As storms work
east overnight into Wednesday, storms may start to run into the cap
with building heights so have lower pops in the east than in the
initial source region.  With the warming temperatures aloft, highs
should be a few degrees warmer than on Tuesday.  The biggest
difference however will be the increased humidity levels as dew
points climb throughout the day.  This will lead to increased
elevated instability throughout the day.

.LONG TERM...(Wednesday Evening through Monday)
Issued at 352 AM CDT Tue Jun 25 2019

On Wednesday evening, low level jet develops across the plains, with
the forecast area on the nose of the jet.  With atmosphere only
weakly capped, have raised pops into the likely range across
southwest Minnesota where the mass-convergence appears to be
strongest.  With dry adiabatic lapse rates above 700 mb, have enough
instability to possibly lead to severe storms.  Wind shear is fairly
limited and unidirectional, limiting 0-6 km bulk shear to 20-25
knots.

Temperatures on Thursday are somewhat tricky depending on how
quickly clouds/convection work east. Low level jet once again
develops across the central portions of the US more focused on Iowa.
 Therefore, have limited pops mainly focused in the east Thursday
night.

Thereafter, looks warm and mainly dry with 850 hpa temps warming
into the 20s and remaining there well into next week, and possibly
into the 4th of July holiday.   Upper ridge is threatened a bit by
sporadic ridge riders, so still have a few chances of thunderstorms,
mainly concentrated into the overnight hours.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1202 PM CDT Tue Jun 25 2019

VFR conditions expected for the upcoming 12 or more hours. We`ll
monitor thunderstorms across the western Dakotas move towards the
area later tonight, which could impact the terminals. Confidence
too low to include at this point, but further mention in the 00Z
TAF may be possible.



&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&

$$

SHORT TERM...BT
LONG TERM...BT
AVIATION...Dux



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